1. Field of the Invention
The invention relates to a driving apparatus, more particularly to a driving apparatus used for operating a sunshade and having a vibration limiter.
2. Description of the Related Art
FIGS. 1 and 2 illustrate a conventional vehicle sunshade device 1 that includes a base seat 11, a shaft 12 mounted rotatably on the base seat 11, a curtain 13 rolled around the shaft 12 and having an end rod 14 attached thereto, a pair of support rods 15 connected between the base seat 11 and the end rod 14 for unrolling the curtain 13, and a driving apparatus 16 for extending or retracting the support rods 15.
The driving apparatus 16 includes a housing 161, a gear assembly 162 mounted inside the housing 161, a pair of racks 163 disposed in parallel to each other and driven by the gear assembly 162 to move the support rods 15 in opposite directions, and a drive unit 164 for driving the gear assembly 162. The drive unit 164 includes a motor 165 and a worm gear 167 connected to an output shaft 166 of the motor 165.
When the motor 165 is activated, the worm gear 167 rotates the gear assembly 162 and thereby drives the racks 163 to move toward or away from each other. Accordingly, the support rods 15 are retracted or extended, and the curtain 13 is rolled and unrolled.
Because the worm gear 167 is assembled with the output shaft 166 of the motor 165 through a rivet connection, the worm gear 167 is likely to vibrate and rattle against a meshing gear of the gear assembly 162 during its operation due to assembly or manufacturing errors. In particular, the worm gear 167 vibrates substantially at a suspended free end 168 thereof. As a result, unbalanced motions are incurred in the gear assembly 162.